The overall goal of the research proposed in this application is to determine the spatiotemporal patterns of functional activation of cortical areas during performance of specific perceptual-motor cognitive tasks, as revealed by high field strength (4 Tesla) magnetic resonance imaging (4T- mRI). Healthy human subjects will be studied. The tasks are designed to test specific hypotheses of how two major classes of cognitive processes, including mental rotation and memory scanning, are represented in the brain. The potential achievement of these objectives is within reach, due to the high spatial and temporal resolution afforded by the 4T-MRI. The specific aims are to (a) identify the areas involved during mental rotation and memory scanning, and (b) test the hypotheses that these cognitive processes involve (i) the sequential activation of specific cortical areas and (ii) the activation of certain common cortical areas. It is expected that these studies will partially elucidate the dynamical neural correlates involved in these two different kinds of cognitive processes.